JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 252 · 40 questions

Code tip (Line by line): let x = 5; makes a variable x holding 5; x = x + 2; changes it to 7. console.log(…) writes in the console; alert(…) shows a pop-up box. Text in quotes + anything = joined text: "5" + 3 → "53".

1. 1.⚡ What does this code show?
   let name = "Meera";
   alert("Welcome, " + name + "!"); (a) name (b) Welcome, Meera! (c) Meera (d) Welcome, name!
2. 2.⚡ Which JavaScript word shows a pop-up box? (a) if (b) console.log() (c) let (d) alert()
3. 3.⚡ What number does this code print?
   let a = 22;
   let b = 17;
   console.log(a + b);
4. 4.⚡ Which word makes a new variable? (a) give (b) let (c) make (d) put
5. 5.⚡ Where does console.log() show its output? (a) in the address bar (b) in the console (c) on the title bar (d) on the printer
6. 6.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <js> (c) <style> (d) <code>
7. 7.⚡ Which JavaScript word runs code when true? (a) for (b) console.log() (c) alert() (d) if
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 1;
   console.log(x + y); (a) 81 (b) Error (c) 9
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 3;
   console.log(x + y); (a) 12 (b) 93 (c) Error
10. 10.⚡ What does this code show?
    let name = "Kabir";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Well done, Kabir! (d) Kabir
11. 11.⚡ What number does this code print?
    let a = 9;
    let b = 22;
    console.log(a + b);
12. 12.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .js (c) .css (d) .html
13. 13.⚡ What does JavaScript add to a web page? (a) only colours (b) the domain name (c) the page title (d) actions and changes
14. 14.⚡ What number does this code print?
    let a = 19;
    let b = 20;
    console.log(a + b);
15. 15.⚡ What does this code show?
    let name = "Riya";
    console.log("Welcome, " + name + "!"); (a) Welcome, Riya! (b) name (c) Welcome, name! (d) Riya
16. 16.⚡ What number does this code print?
    let a = 57;
    let b = 22;
    console.log(a + b);
17. 17.⚡ What number does this code print?
    let a = 8;
    let b = 3;
    console.log(a - b);
18. 18.⚡ What number does this code print?
    let a = 3;
    let b = 2;
    console.log(a * b);
19. 19.⚡ What number does this code print?
    let runs = 24;
    runs = runs + 8;
    runs = runs - 6;
    console.log(runs);
20. 20.⚡ What number does this code print?
    let a = 23;
    let b = 23;
    console.log(a - b);
21. 21.⚡ What number does this code print?
    let marks = 8;
    marks = marks + 15;
    marks = marks - 20;
    console.log(marks);
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 2;
    console.log(x + y); (a) Error (b) 4 (c) 22
23. 23.⚡ What number does this code print?
    let runs = 29;
    runs = runs + 10;
    runs = runs - 34;
    console.log(runs);
24. 24.⚡ What does alert() show? (a) a pop-up box (b) a table (c) a new tab (d) a picture
25. 25.⚡ What number does this code print?
    let a = 15;
    let b = 11;
    console.log(a - b);
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 3;
    console.log(x + y); (a) 43 (b) Error (c) 7
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 8;
    console.log(x + y); (a) 10 (b) 28 (c) Error
28. 28.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) name (b) Riya (c) Welcome, Riya! (d) Welcome, name!
29. 29.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Aman (c) Welcome, Aman! (d) name
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 4;
    console.log(x + y); (a) 12 (b) 84 (c) Error
31. 31.⚡ What number does this code print?
    let a = 47;
    let b = 12;
    console.log(a - b);
32. 32.⚡ What number does this code print?
    let a = 8;
    let b = 12;
    console.log(a * b);
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 2;
    console.log(x + y); (a) 82 (b) 10 (c) Error
34. 34.⚡ What does this code show?
    let name = "Arjun";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Arjun (d) Welcome, Arjun!
35. 35.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) name (b) Kabir (c) Hello, name! (d) Hello, Kabir!
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 5;
    console.log(x + y); (a) Error (b) 12 (c) 75
37. 37.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Aman (c) name (d) Well done, Aman!
38. 38.⚡ What number does this code print?
    let a = 5;
    let b = 13;
    console.log(a + b);
39. 39.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Meera! (d) Meera
40. 40.⚡ What number does this code print?
    let a = 7;
    let b = 5;
    console.log(a * b);

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